161.29% is the change from 31 to 81
Calculation steps:
[( 81 - 31 ) ÷ 31] x 100 = 161.29%
Formula
Percentage change = [(81 - 31) / 31] x 100
Subtract the new number by the original number
81 - 31 = 50
50 ÷ 31 = 1.6129032258064515
1.6129032258064515 x 100 = 161.29%